Utilization of side shields in write heads can affect in cross-track gradients and therefore areal density. The use of side shields can however cause side track erasure (STE). STE can be caused by a number of phenomena including flux leakage through the flare angle into the side shields and into the media.
The figures are not necessarily to scale. Like numbers used in the figures refer to like components. However, it will be understood that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number.